This invention provides processes for preparing certain valuable substances useful in the formation of perfume materials. More specifically, this invention provides a process for preparing substituted oxyacetaldehydes and acetals thereof. The substituted oxyacetaldehydes have the formula: ##STR2## and the substituted oxyacetaldehyde acetals have the formula: ##STR3## wherein R.sub.1 and R.sub.2, taken separately are each the same or different lower alkyl or R.sub.1 and R.sub.2, taken together, represent a lower alkylene moiety; and where R.sub.3 is alkyl, alkenyl and alkadienyl.
Examples of the compounds prepared according to the process of this invention are the aldehydes, citronellyl oxyacetaldehyde, geranyl oxyacetaldehyde and n-octyl oxyacetaldehyde. Corresponding methyl and ethyl acetals are also examples of the compounds prepared according to the process of the instant invention.
Citronellyl oxyacetaldehyde, having the structure: ##STR4## is described by Arctander, "Perfume and Flavor Chemicals" (Aroma Chemicals), Vol. I, 1969, #688. This aldehyde is described as having a "powerful and moderately diffusive green-rosey, sweet Lily-Muguet-like odor". As stated by Arctander, citronellyl oxyacetaldehyde is:
"Used in perfume compositions as a floralizing aldehydic topnote ingredient, primarily in Muguet-Lily fragrances, but also in Rose Peony (where the Geranyl-isomer is claimed to be superior), and various modifications of modern-aldehydic fragrance types. PA1 Occasionally used in flavor compositions for floral or fruity types, and in Rose type flavors. The concentration is usually mere traces in the finished product." PA1 "In 1872, Pinner (Ber. 5 (1872) 159) reported the preparation of a number of oxy-acetaldehydes and their acetals by the interaction of bromoacetals with sodium or potassium alcoholates. It was not until 1929, however, that the value of these compounds as perfumery materials was brought to the attention of the industry by Sabetay and co-workers (Bull. Soc. Chim. France, 45 (1929) 1161 and Compt. Rend., 194 (1932) 617 and 196 (1933) 1508). Further work on the preparation of this class of compounds was done by Rothard (Compt. Rend., 196 (1933) 2013; 197 (1933) 1225) and Shoruigin and Korshak (Ber., 68B (1935) 838 and Chem. Abstracts, 29 (1935) 7941), who reported the odor characteristics of many of these compounds."
Arctander states that this material is produced from Citronellol, which is first reacted with sodium methylate or sodium iso-propylate. The thus formed sodium citronellol organometallic compound is then reacted with chlorodimethylacetal to produce the citronellyl oxyacetaldehyde dimethylacetal. The thus formed citronellyl oxyacetaldehyde dimethylacetal is finally hydrolyzed with dilute oxalic acid to yield the desired aldehyde, the citronellyl oxyacetaldehyde.
In monograph 689 of Arctander, "Perfume and Flavor Chemicals" (Aroma Chemicals), Vol. I, 1969, Arctander describes citronellyl oxyacetaldehyde diethylacetal having the formula: ##STR5## This compound is described as having a "very faint, delicate, Rose-Muguet-type odor". It is also stated to be somewhat more oily and more tenacious than the aldehyde, but much weaker.
Bedoukian, "Perfumery and Flavoring Synthetics", Elsevier Publishing Co., 2nd Revised Edition, 1967, describes at page 378 in the section entitled: "The Oxy-Acetaldehydes" various oxyacetaldehydes for use in perfumery, e.g., citronellyl oxyacetaldehyde, geranyl oxyacetaldehyde, phenylethyl oxyacetaldehyde, benzyl oxyacetaldehyde and decyl oxyacetaldehyde and the corresponding acetals. Bedoukian reports that various references describe the preparation of these oxyacetaldehydes and their acetals by interaction of "bromo acetals with sodium or potassium alcoholates". Thus, Bedoukian states:
Neither the references cited by Bedoukian nor the references cited by Arctander disclose the one-step or two-step efficient process of the instant invention (depending on whether acetals or aldehydes are desired to be produced).
In performing the one-step or two-step process of the instant invention, quaternary ammonium salts are used as catalysts or reaction "promoters". Thus, whereas the instant invention discloses and claims the reaction sequence: ##STR6## the prior art, as embodied in Bedoukian and Arctander, discloses the three-step reaction sequence, illustrated thusly:
Arctander and Bedoukian Process Disclosed by: ##STR7## wherein R.sub.3 is alkyl, alkenyl or alkadienyl; wherein R.sub.4 is lower alkyl; wherein M is potassium or sodium; wherein X is chlorine or bromine and wherein R.sub.1 or R.sub.2 are lower alkyl or represent an alkylene moiety.
Production of mixed ethers from alkyl halides and alkanols are disclosed using quaternary ammonium salts in the Eastman Organic Chemicals Bulletin, Vol. 48, #1, 1976, page 2, section entitled: "Unsymmetrical Ethers". In addition, the Eastman Organic Chemicals Bulletin discloses the production of aryl alkyl ethers using quaternary ammonium salts. Nevertheless, the production of the alkyl, alkenyl and alkadienyl oxyacetaldehydes and oxyacetaldehyde acetals is not disclosed, either implicitly or explicitly, by either the Eastman Organic Chemicals Bulletin or any of the other prior art where quaternary ammonium salts are used as reaction promoters. Also relevant is the article, Freedman and Dubois, Tetrahedron Letters, No. 38, pages 3251-3254, 1975, "An Improved Williamson Ether Synthesis Using Phase Transfer Catalysis".